[WP-34S] My first integral on this calculator
05-18-2014, 08:25 PM
Post: #1
 jebem Senior Member Posts: 1,342 Joined: Feb 2014
[WP-34S] My first integral on this calculator
Hi all,
I managed to run my first integral on my new WP-34S!

I must say that, despite using HP RPN calculators since the 70's, I quit using calculators for many years, and only recently started to look again to these devices, by acquiring the 49+, 48GII, 50G and Prime.
So I have missed the HP-15C and 42S series and I was not aware on how to use integrals in these machines.

As the WP-34S is loosely based in the HP-15C and 42S machines, I had to spend some time digging it until I could use the WP-34S as I intended.
I was expecting the WP-34S to be more closer to the 42S than to the 15C, but it seems that this is not the case.

So I took this example where a simple integral is used to compute the "angle of twist" problem from page 125 of the HP-42S Programming Examples guide, and have adapted that HP-42S program code to run in the WP-34S but using the HP-15C style (so, no local variables at all).

I know this is basic stuff for HP-15C / 42S experts, but I believe that probably more people will have the same questions as I had when I tried to take a simple integral in this excellent RPN WP-34S (for me it so much easier to do it using "pretty print"/"equation editors"/"templates" as I do on my HP-Prime, 50G, and even on a Casio FX-991DE Plus...!).

To invoke the integral:
1. Create the program and name it 'TOR'
2. Load the lower and upper limits Limits (in this example, Lower (Y):0 Upper (X):2
3. Invoke it from the entry mode: h + 2 ENTER TOR

WP-34S result: 0.02805957296 (HP-42S result as stated in the guide: 0.0281)
Time to complete: about 5 seconds

My WP-34S program code for the "Angle of twist" problem:
LBL'TOR'
1
3
*
8
+
*
1
5
+
*
9
+
*
6
+
7
.
9
5
2
1
EEX
8
+/-
/
8
3
EEX
9
/
RTN
END

Jose Mesquita